A woman was crushed to death on Sunday after falling through a floor panel at the top of an escalator in a department store in central China.

The woman, aged 30, was carrying her toddler son up the escalator in the store in Hubei province when the floor at the top gave way under her feet.

She managed to shove her son to safety as she was slowly dragged downwards, CCTV footage of the incident posted online shows.

One of the two shop assistants who witness the incident at the top of escalator tries but fails to pull the woman out, while the other assistant hurries the boy away.

According to the Wuhan Evening News, a local paper, maintenance work had been carried out on the escalator at the Anliang shopping mall in Jingzhou, but workers had allegedly forgotten to secure the panel back in place.

It took firefighters more than four hours to access the escalator to recover the body, which showed “no sign of life”.

The tragic incident has fuelled outrage on Chinese social media. It was one of the top topics on Sina Weibo, a microblogging platform, on Monday, with millions of views and comments.

“This is heartbreaking!” one user, Maqi Yaduo wrote. “Why didn’t store employees cordon off or shut down the escalator? The department store is definitely responsible for this.”

Public health and safety is often found wanting in China, as standards are unenforced and sufficient checks are not made.

In 2012 a nine-year-old boy was crushed to death in an escalator in a Beijing department store, to the horror of legions of shoppers.

A 13-year-old boy died and 29 other people were injured in 2011 when an escalator in a Beijing subway station suddenly reversed direction during rush hour.

“I used to think only lifts would kill people – now it looks like escalators aren’t safe either,” one weibo user wrote. “Next time I’m on an escalator, I’ll jump across [the top].”